| APA | NNPO. (2012, February 16). In Acronym Geek. Retrieved 06:14, February 16, 2012, from http://www.acronymgeek.com/NNPO |
| MLA | "NNPO." Acronym Geek. (2012). Acronym Geek. 16 Feb 2012 <http://www.acronymgeek.com/NNPO>. |
| MHRA | 'NNPO', Acronym Geek, 16 February 2012, <http://www.acronymgeek.com/NNPO> [accessed 16 February 2012] |
| Chicago | "NNPO", http://www.acronymgeek.com/NNPO (accessed February 16, 2012). |
| CBE/CSE | NNPO [Internet]. Acronym Geek; 2012 Feb 16 [cited 2012 Feb 16]. Available from: http://www.acronymgeek.com/NNPO. |
| Bluebook | NNPO, http://www.acronymgeek.com/NNPO (last visited February 16, 2012). |
| Bluebook: Harvard JOLT | See Acronym Geek, NNPO, http://www.acronymgeek.com/NNPO (optional description here) (as of Feb. 16, 2012, 06:14). |
| AMA | NNPO. Acronym Geek. February 16, 2012, 06:14. Available at: http://www.acronymgeek.com/NNPO. Accessed February 16, 2012, 06:14. |